Lighting fixture



AprEE I, 194?". MARGQLIS I 2,418,131

LIGHTING FIXTURE Filed July 15. 1944 Patented Apr. 1, 1947 UNITED STATESPATENT OFFICE (Granted under the act of March 3, 1883, as amended April30, 1928; 370 0. G.'757) 2 Claims.

The invention described herein, if patented, may be manufactured andused by or for the Government for governmental purposes, without thepayment to me of any royalty thereon.

The invention relates to a lighting fixture of the type having aninverted bowl reflector and a silver bowl lamp. Forming a. part of thefixture is an auxiliary reflector, designed to reflect a portion of thelight toward the ceiling.

For the purpose of lighting hallways and large rooms, the use ofindirect lighting has been largely superseded by the inverted bowlreflector with a silver bowl light bulb. It was a fault of indirectlighting that insuflicient illumination of the floor and details of theside-wall, such as room numbers, name cards, etc., resulted, andsufficient light for desk work was seldom provid ed. Furthermore, if theceiling became darkened with dust and soot the general level ofillumination was seriously reduced.

The inverted bowl reflector, as employed with a silver bowl lamp,produces a highly desirable form of illumination, since the silver bowlof the lamp prevents glare from the direct rays of the lamp and the bowlreflector catches and deflects the rays from the lamp in a desirablepattern for effective illumination of all the lower portion of the roomor hall. There is difiiculty in securing satisfactory illumination ofthe ceiling when only an inverted bowl reflector is used. A certainamount of ceiling illumination is desirable, both to improve the genera1i1lumination of the room and to avoid an unpleasant dark shadow on theceiling above each suspended light. This problem has not been solvedwith the inverted bowl reflector and silver bowl lamp fixtures employedat present. Similar types of units now available on the market producetoo high surface brightness on the reflecting surface causingobjectionable glare and eye fatigue. Also these units provide no meansof lighting the ceiling, thus creating too great a contrast. Thisinvention is so designed as to have low surface brightness on the mainreflector and is provided with an auxiliary reflector of opaque materialto light up the ceiling.

It is an object of this invention to provide a new reflecting fixture ofthe inverted bowl reflector and silver bowl lamp type which insures asatisfactory mounting for the reflector on the lamp bulb support andprovides a better configuration of reflector and an effectivepositioning of the reflector with respect to the lamp.

It is a further object of the invention to provide a lighting fixture ofthe inverted bowl reflector and silver bowl lamp type having anauxiliary reflector attached to the lower rim of the bowl for lightingthe ceiling adjacent to the fixture.

It is a further object of the invention to provide a lighting fixturewhich avoids the disadvantages inherent in the indirect lightingfixtures still employed in many public buildings, and which combines theadvantages of good ceiling illumination with the advantages of theinverted bowl type of reflector.

It is a further object of this invention to design a lighting unit ofhigh efliciency having low surface brightness and being free ofobjectionable glare.

Further objects of the invention will be apparent from a considerationof the detailed description of the invention, taken in connection withthe accompanying drawing in which:

Figure l is a top plan view of the lighting fiX- ture, showing theauxiliary reflector attached to the inverted bowl reflector;

Figure 2 is a side view of the lighting fixture partly in elevation andpartly in section.

Figure 3 is a fragmentary side view of a portion of the two reflectorsin slightly separated relation.

As shown in the drawing, the invention utilizes a silver bowl electriclamp Hi, which should be of large size, 360 watts or more, for use in oiflces and public buildings. The light it is sup-- ported at the end of adependin pipe I I by means of the usual socket 12, over which a husk i3is supported in inverted relation. The husk 13 extends slightly belowthe juncture of the lamp with the socket, and is provided ordinarilywith bayonet slots to support a shade or reflector. The parts requiredfor this assembly are,

% to hi y /8 ball alisner Canopy Stem Husk

Mogul porcelain screw base socket 300 watt silver bowl lamp The mainreflector comprises an inverted bowl lit, formed preferably of spunmetal or plastic and having a suitable flat white reflecting surface,which may be a baked matte finish. The main part of the reflector M is asmoothly curving bowl of the configuration shown, which effects an evendistribution of the light over the area to be lighted. The center of thereflector is formed with a smoothly curved, downwardly depending portionI5, slightly longer than half the depth of the reflector and having anopening at its lower end to receive the husk I3 of the suspended lamp.Means such as headed bolts 16 are provided on the conical projection isto engage in the bayonet slots of the husk l3 to support the'reflector44 on the lamp fixture.

The lamp bulb is silvered over the lower portion H, as shown in thedrawing, and the lower edge I8 of the bowl reflector terminates in theplane of the top of the silvered reflector area I! of the lamp. The topof the reflector 14 is preferably of a height to reach the top of thelamp socket 12.

The auxiliary reflector 19 comprises a smoothly curving ring or annularmember having the same reflecting structure as the bowl reflector. It issupported from the lower rim of the bowl reflector It by means of chains20 secured in apertures 2! in the rim of the bowl reflector l4 and tobracket members 22 on the reflecting face of the auxiliary reflector.The auxiliary reflector I9 is thus supported in spaced relation to thebowl reflector M, with its lower edge 23 almost directly below the rimof the bowl reflector and approximately even with the lower tip 24 ofthe lamp l6 and its upper edge 25 outside of but in the same horizontalplane as, the lower edge of the bowl Hi.

The outside diameter of the bowl reflector would ordinarily be about23", and the outside diameter of the auxiliary reflector about 30".

There is thus provided a means for deflecting part of the rays from thelamp upwardly through th space between the two reflectors. This providesa satisfactory illumination of the ceiling above the lamp withoutmaterially lessening the lower area illumination provided by theinverted bowl. The reflector is designed in such a way as to be almostradial in design, and thus light striking it will give an evenbrightness. By referring to the drawing, it will be noted that beam Astrikes reflector l4 and is reflected down in a general difiusingmanner. Beam B is redirected down and at an angle. Beam C strikin theside of reflector I4 is directed at nearly a horizontal angle, affordingwide distribution to the light from the unit. All the light striking theauxiliary reflector I9 is diffused light from the reflector l4 and fromthe neck of the silver bowl lamp 19. The reflector I9 is so designed asto light the ceiling at approximately an even intensity. It will benoted that none of the principal beams of the source are used for thispurpose, but all of the principal beams are utilized for the reflector Il.

It will be seen, that in the use of a fixture of this type no rayscoming directly from the lamp can reach the eyes of persons occupying orpassing through the areas lighted thereby. At the same time, the lightis reflected in an even pattern from the various inner surfaces of thebowl reflector to produce a brilliant light, but one that is diffused tosuch an extent that are is avoided. It will be observed that the unit ishighly efficient, as all of the useful light from the source reaches themain reflector, which in turn redirects it to the plane of utilization.Since this is a direct lighting fixture, and the main reflector curvesdown, the maintenance will be '4 very low. Also, the auxiliary reflectoris shielded against direct light rays from the bulb by means of thesilvered reflector means associated with the bulb, and thus receives itslight only from spill and diffusion, thus not lowering the efficiency ofthe main reflector by intercepting the light that would normally reachit. The auxiliary reflector provides for illumination of the ceiling toan extent sufficient to avoid shadow and also to complete the generalpattern of illumination by reflection from the ceiling.

While I have illustrated and described the preferred embodiment of myinvention, it is to be understood that I do not limit myself to theprecise construction herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdefined in the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A lighting fixture comprising an annular reflector concave downwardlyin cross section,- a light socket, means for supporting said reflectoron the light socket, an upwardly flaring annular auxiliary reflector ofopaque material having its lower rim substantially the same size as thelower rim of said first-mentioned reflector, means for supporting saidauxiliary reflector beneath the first-mentioned reflector with the upperrim of the second-mentioned reflector in the horizontal plane of thelower rim of said first-mentioned reflector and outwardly thereof, and asilver bowl lamp bulb in said socket, the silvered area of the bulblying within the horizontal planes defined by the rims of thesecond-mentioned reflector;

2. A lighting fixture comprising an annular reflector concave downwardlyin crosssection, a light socket, a lamp bulb in said socket, means forsupporting said reflector on the light socket, an upwardly flaringannular auxiliary reflector of opaque material having its lower rimsubstantially the same size as the lower rim of said firstmentionedreflector, means supporting said auxiliary reflector from and beneaththe first-men tioned reflector with the upper rim of the secondmentionedreflector substantially in the horizons tal plane of the lower rim ofsaid first-mentioned reflector and outwardly thereof, and a reflectorsurrounding the lower portion of the lamp bulb, the area of saidlast-mentioned reflector lying within the horizontal planes defined bythe rims of the second-mentioned reflector.

LOUIS MARGOLIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Baumgartner Jan. 10, 1939

